// Tags:
#include <cctype>
#include <cstdio>

template <typename T>
inline T &read(T &x) {
  x = 0;
  bool f = false;
  short ch = getchar();
  while (!isdigit(ch)) {
    if (ch == '-') f = true;
    ch = getchar();
  }
  while (isdigit(ch)) x = (x << 1) + (x << 3) + (ch ^ '0'), ch = getchar();
  if (f) x = -x;
  return x;
}

const int N = 2e3 + 5;
int n, t;
double p, f[N][N];

int main() {
#ifndef ONLINE_JUDGE
#ifdef LOCAL
  freopen64("/tmp/CodeTmp/testdata.in", "r", stdin);
  freopen64("/tmp/CodeTmp/testdata.out", "w", stdout);
#else
  freopen("waterfall.in", "r", stdin);
  freopen("waterfall.out", "w", stdout);
#endif
#endif

  read(n);
  scanf("%lf", &p);
  read(t);
  f[0][0] = 1;
  for (int i = 1; i <= t; ++i) {
    for (int j = 0; j < n; ++j) {
      if (j > 0) f[i][j] += p * f[i - 1][j - 1];
      f[i][j] += (1.0 - p) * f[i - 1][j];
    }
    f[i][n] += p * f[i - 1][n - 1];
    f[i][n] += f[i - 1][n];
  }
  double ans = 0;
  for (int i = 1; i <= n; ++i) { ans += f[t][i] * i; }
  printf("%.7lf", ans);
  return 0;
}